Vibrio Cholerae non-O1 Research Articles

Complete genome sequences of sucrose non-fermenting non-O1/non-O139 Vibrio cholerae isolated from human soft tissue infection.

This paper describes the hybrid genome assembly of sucrose non-fermenting non-O1/non-O139 Vibrio cholerae isolated from human soft tissue infection. The hybrid assembled genome comprises two circular chromosomes with lengths of 3,001,999 bp and 1,264,051 bp, respectively, with a G + C content of 47.38%.

Public health aspects of Vibrio spp. related to the consumption of seafood in the EU.

Vibrio parahaemolyticus, Vibrio vulnificus and non-O1/non-O139 Vibrio cholerae are the Vibrio spp. of highest relevance for public health in the EU through seafood consumption. Infection with V. parahaemolyticus is associated with the haemolysins thermostable direct haemolysin (TDH) and TDH-related haemolysin (TRH) and mainly leads to acute gastroenteritis. V. vulnificus infections can lead to sepsis and death in susceptible individuals. V. cholerae non-O1/non-O139 can cause mild gastroenteritis or lead to severe infections, including sepsis, in susceptible individuals. The pooled prevalence estimate in seafood is 19.6% (95% CI 13.7-27.4), 6.1% (95% CI 3.0-11.8) and 4.1% (95% CI 2.4-6.9) for V. parahaemolyticus, V. vulnificus and non-choleragenic V. cholerae, respectively. Approximately one out of five V. parahaemolyticus-positive samples contain pathogenic strains. A large spectrum of antimicrobial resistances, some of which are intrinsic, has been found in vibrios isolated from seafood or food-borne infections in Europe. Genes conferring resistance to medically important antimicrobials and associated with mobile genetic elements are increasingly detected in vibrios. Temperature and salinity are the most relevant drivers for Vibrio abundance in the aquatic environment. It is anticipated that the occurrence and levels of the relevant Vibrio spp. in seafood will increase in response to coastal warming and extreme weather events, especially in low-salinity/brackish waters. While some measures, like high-pressure processing, irradiation or depuration reduce the levels of Vibrio spp. in seafood, maintaining the cold chain is important to prevent their growth. Available risk assessments addressed V. parahaemolyticus in various types of seafood and V. vulnificus in raw oysters and octopus. A quantitative microbiological risk assessment relevant in an EU context would be V. parahaemolyticus in bivalve molluscs (oysters), evaluating the effect of mitigations, especially in a climate change scenario. Knowledge gaps related to Vibrio spp. in seafood and aquatic environments are identified and future research needs are prioritised.

Study on Antibiotic Resistance Profiles Exhibited by Vibrio Species Isolated from Landfill Soils in Zaria Metropolis, Northern Nigeria

Study’s Novelty/Excerpt This study investigates the occurrence and antibiotic resistance profiles of Vibrio species isolated from landfill soils in Zaria Metropolis, with a focus on environmental reservoirs of antibiotic resistance. The research uniquely identifies a high prevalence of Vibrio cholerae non-O1 among the isolates and reveals significant multidrug resistance (MDR), particularly against Ampicillin, while also showing complete susceptibility to Gentamicin and Chloramphenicol. These findings highlight the potential for landfills to serve as environmental reservoirs of antibiotic resistance, underscoring the need for further research to understand the implications for public health and environmental management. Full Abstract Antibiotic resistance in bacteria presents a major risk to public health and the environment. Infections caused by Vibrio species continue to be a serious public health concern. This study investigated the occurrence and antibiotic resistance profiles of Vibrio species isolates from landfill soils in Zaria Metropolis. A total of one hundred and twenty (120) soil samples were collected from designated landfills in four locations in Sabon-Gari, Samaru, Tudun-Wada, and Zaria City. Vibrio species were isolated using Thiosulphate citrate bile salt sucrose (TCBS) agar. Bacteriological analysis of the soil samples revealed 9(7.50%) Vibrio species isolates with Vibrio cholerae non-O1 exhibiting the highest prevalence of 4 (3.33%) among all isolates. Using the Kirby-Bauer method, the isolates were tested for susceptibility against ten commonly used antibiotics belonging to three different classes. The highest resistance was to Ampicillin (88. 89%), while all the isolates (100%) showed susceptibility to Gentamicin and Chloramphenicol. Five isolates (55.56%) were Multidrug Resistance (MDR). The highest Multidrug Resistance (MDR, 60%) was observed in Vibrio cholerae non-O1. The isolate resistant to the highest number of antibiotics was obtained from the Tudun-Wada sample location. Three isolates (33.33%) showed resistance to 4 antibiotics, while 2 isolates, 1(11.11%) each were resistant to 5 and 6 antibiotics. The isolates were Multiple Antibiotic Resistance (MAR) to 4-6 antibiotics, and four different phenotypic resistance profiles were observed among them. The origin and varying levels of resistance to multiple antibiotics indicated could be traced to the faecal constituent of the waste in landfills produced by people or animals that have been treated indiscriminately with various antibiotics or items containing residual antimicrobial agents disposed of in dump soils, highlighting the potential environmental reservoirs of antibiotic resistance and call for further research to understand the implications for public health and environmental management.

Epidemiological and genetic characterization of multidrug-resistant non-O1 and non-O139 Vibrio cholerae from food in southern China

This study reports a comprehensive epidemiological and genetic analysis of V. cholerae strains, specifically non-O1/non-O139 serogroups, isolated from animal-derived food samples in Guangdong province from 2015 to 2019. A total of 21 V. cholerae strains were obtained, which exhibited high resistance rates for nalidixic acid (57.14 %, 12/21), ampicillin (33.33 %, 7/21), and ciprofloxacin (19.05 %, 4/21). The quinolone resistance-related gene, qnrVC, was prevalent in 80.95 % (17/21) of the isolates. Additionally, chromosomally mediated quinolone-resistance mutations, including mutations in GyrA at position 83 (S83I) and ParC at position 85 (S85L), were detected in 47.62 % of the isolates. The combination of target mutation and qnrVC genes was shown to mediate resistance or intermediate resistance to ciprofloxacin in V. cholerae. Furthermore, an IncC-type conjugative plasmid carrying thirteen antibiotic resistance genes, including genes conferring resistance to two clinically important antibiotics, cephalosporins and fluoroquinolones, was identified in the shrimp-derived strain Vc516. While none of our food isolates harbored the toxigenic CTX- and TCP-encoding genes, they did possess genes encoding toxins such as HlyA and Autoinducer-2. Notably, some V. cholerae strains from this study exhibited a close genetic relationship with clinical strains, suggesting their potential to cause human infections. Taken together, this study provides a comprehensive view of the epidemiological features and genetic basis of antimicrobial resistance and virulence potential of V. cholerae strains isolated from food in southern China, thereby advancing our understanding of this important pathogen.

Non-O1/Non-O139 Vibrio cholerae-An Underestimated Foodborne Pathogen? An Overview of Its Virulence Genes and Regulatory Systems Involved in Pathogenesis.

In recent years, the number of foodborne infections with non-O1 and non-O139 Vibrio cholerae (NOVC) has increased worldwide. These have ranged from sporadic infection cases to localized outbreaks. The majority of case reports describe self-limiting gastroenteritis. However, severe gastroenteritis and even cholera-like symptoms have also been described. All reported diarrheal cases can be traced back to the consumption of contaminated seafood. As climate change alters the habitats and distribution patterns of aquatic bacteria, there is a possibility that the number of infections and outbreaks caused by Vibrio spp. will further increase, especially in countries where raw or undercooked seafood is consumed or clean drinking water is lacking. Against this background, this review article focuses on a possible infection pathway and how NOVC can survive in the human host after oral ingestion, colonize intestinal epithelial cells, express virulence factors causing diarrhea, and is excreted by the human host to return to the environment.

German coasts harbor non-O1/non-O139 Vibrio cholerae with clinical virulence gene profiles

Non-O1/non-O139 Vibrio cholerae (NOVC) are ubiquitous in aquatic ecosystems. In rare cases, they can cause intestinal and extra-intestinal infections in human. This ability is associated with various virulence factors. The presence of NOVC in German North Sea and Baltic Sea was observed in previous studies. However, data on virulence characteristics are still scarce. Therefore, this work aimed to investigating the virulence potential of NOVC isolated in these two regions. In total, 31 NOVC strains were collected and subjected to whole genome sequencing. In silico analysis of the pathogenic potential was performed based on the detection of genes involved in colonization and virulence. Phenotypic assays, including biofilm formation, mobility and human serum resistance assays were applied for validation. Associated toxin genes (hlyA, rtxA, chxA and stn), pathogenicity islands (Vibrio pathogenicity island 2 (VPI-II) and Vibrio seventh pathogenicity island 2 (VSP-II)) and secretion systems (Type II, III and VI secretion system) were observed. A maximum likelihood analysis from shared core genes revealed a close relationship between clinical NOVCs published in NCBI and environmental strains from this study. NOVC strains are more mobile at 37 °C than at 25 °C, and 68% of the NOVC strains could form strong biofilms at both temperatures. All tested strains were able to lyse erythrocytes from both human and sheep blood. Additionally, one strain could survive up to 60% and seven strains up to 40% human serum at 37 °C. Overall, the genetic virulence profile as well as the phenotypic virulence characteristics of the investigated NOVC from the German North Sea and Baltic Sea suggest potential human pathogenicity.

Non-O1/non-O139 Vibrio cholerae bacteraemia and cholangitis: An unusual case in an oncological patient in Lecco Hospital, Italy

Vibrio species are curved, motile, aerobic and facultative anaerobic, Gram-negative bacilli that are widely distributed in aquatic environments, especially marine and estuarine waters. Vibrios of primary concern in human pathology are essentially represented by the species Vibrio cholerae. Classification of Vibrio cholerae is based on the O-antigen polysaccharide type, with over 200 serogroups described. Historically, only toxigenic serogroups O1 and O139 have been associated with widespread cholera epidemics. Other serogroups can cause small outbreaks that spread via contaminated raw seafood (primarily shellfish and molluscs) and seawater exposure, and they are collectively termed Non-O1/Non-O139 Vibrio Cholerae (NOVC). NOVC, occasionally detected also in the Mediterranean Sea, most often causes sporadic gastrointestinal manifestations requiring supportive therapy. However, rarely the V. cholerae non-O1/ non-O139 serotype can result in extraintestinal manifestations such as severe wound infections, soft tissue infections and sepsis in immunocompromised patients that represent a therapeutic challenge. In particular, NOVC bacteraemia is a rare event but has the highest mortality rates among NOVC infections (almost 33%) and usually occurs in certain immunosuppressed populations, such as patients with haematologic and solid malignancies, and those with underlying liver disease.

Effective inhibition of bacterial sialidases by phenolic acids and flavonoids

As a pathogenicity factor in some microorganisms, sialidase is a key target for inactivation, as this would have curative and preventive effects on various diseases. Significant results are already achieved with viral sialidase inhibitors, while such studies on bacterial enzymes are scarce. Pure natural compounds representing phenols and flavonoids, were tested for their inhibitory effect on sialidases from Vibrio cholerae non-O1, Arthrobacter nicotianae and Oerskovia paurometabola. All three enzymes were isolated, purified beforehand and stored under suitable conditions. Quinic and gallic acids showed the highest inhibitory activity - 76 to 100% against the three sialidases. Fisetin had a significant inhibitory activity on two of the enzymes. The structurally related thymol and thymoquinone exerted from 80 to 100% inhibition on at least one of the enzymes. Catechin and rutin had significant inhibitory activity, varying from 49 to 100%, on some of the enzymes. Quercetin, known for its inhibitory effect on viral sialidases, had a lesser impact on the studied enzymes. The suppressive effect of quinic acid, rutin and fisetin on bacterial sialidases is observed for the first time.

IncA/C plasmid encoding blaCTX-M-55 in non-O1 Vibrio cholerae isolates from the edible river fish Mastacembelus sp.

Extended-spectrum β-lactamase-producing non-O1 Vibrio cholerae was isolated from edible Mastacembelus sp. in Vietnam. The genome sequence was sequenced using DNBSEQ-G400 and MinION Mk1b. A plasmid of approximately 183-kb encoding blaCTX-M-55 and blaTEM-1 was detected.

Meningoencephalitis caused by Non-O1, non-O139 Vibrio cholerae in an infant from southern Spain

Non-O1, non-O139 Vibrio cholerae (NOVC) is an emergent pathogen that mainly causes gastroenteritis. Also, it causes ear, wound infections, and bacteremia but the nervous system is rarely affected. We report on a case of NOVC meningoencephalitis in an infant that recovered after antimicrobial therapy but later presented neurologic sequelae.

Virulence and resistance patterns of Vibrio cholerae non-O1/non-O139 acquired in Germany and other European countries

Global warming has caused an increase in the emergence of Vibrio species in marine and estuarine environments as well as fresh water bodies. Over the past decades, antimicrobial resistance (AMR) has evolved among Vibrio species toward various antibiotics commonly used for the treatment of Vibrio infections. In this study, we assessed virulence and resistance patterns of Vibrio cholerae non-O1/non-O139 strains derived from Germany and other European countries. A total of 63 clinical and 24 environmental Vibrio cholerae non-O1/non-O139 strains, collected between 2011 and 2021, were analyzed. In silico antibiotic resistances were compared with resistance phenotypes according to EUCAST breakpoints. Additionally, genetic relatedness between isolates was assessed by two cgMLST schemes (SeqSphere +, pubMLST). Both cgMLST schemes yielded similar results, indicating high genetic diversity among V. cholerae non-O1/non-O139 isolates. Some isolates were found to be genetically closely related (allelic distance < 20), which suggests an epidemiological link. Thirty-seven virulence genes (VGs) were identified among 87 V. cholerae non-O1/non-O139 isolates, which resulted in 38 virulence profiles (VPs). VPs were similar between clinical and environmental isolates, with the exception of one clinical isolate that displayed a higher abundance of VGs. Also, a cluster of 11 environmental isolates was identified to have the lowest number of VGs. Among all strains, the predominant virulence factors were quorum sensing protein (luxS), repeats-in-toxins (rtxC/rtxD), hemolysin (hlyA) and different type VI secretion systems (T6SS) genes. The genotypic profiles revealed antibiotic resistance genes (ARGs) associated with resistance to beta-lactams, quinolones, macrolides, tetracycline, antifolate, aminoglycosides, fosfomycin, phenicols and sulfonamide. Carbapenemase gene VCC-1 was detected in 10 meropenem-resistant V. cholerae non-O1/non-O139 isolates derived from surface water in Germany. The proportion of resistance among V. cholerae non-O1/non-O139 species isolates against first line treatment (3rd generation cephalosporin, tetracycline and fluoroquinolone) was low. Empirical treatment would likely have been effective for all of the clinical V. cholerae non-O1/non-O139 isolates examined. Nevertheless, carbapenem-resistant isolates have been present in fresh water in Germany and might represent a reservoir for ARGs. Monitoring antimicrobial resistance is crucial for public health authorities to minimize the risks for the human population.

Genetic and Phenotypic Virulence Potential of Non-O1/Non-O139 Vibrio cholerae Isolated from German Retail Seafood.

Non-O1 and non-O139 Vibrio cholerae (NOVC) can cause gastrointestinal infections in humans. Contaminated food, especially seafood, is an important source of human infections. In this study, the virulence potential of 63 NOVC strains isolated from retail seafood were characterized at the genotypic and phenotypic levels. Although no strain encoded the cholera toxin (CTX) and the toxin-coregulated pilus (TCP), several virulence factors, including the HlyA hemolysin, the cholix toxin ChxA, the heat-stable enterotoxin Stn, and genes coding for the type 3 and type 6 secretion systems, were detected. All strains showed hemolytic activity against human and sheep erythrocytes: 90% (n = 57) formed a strong biofilm, 52% (n = 33) were highly motile at 37 °C, and only 8% (n = 5) and 14% (n = 9) could resist ≥60% and ≥40% human serum, respectively. Biofilm formation and toxin regulation genes were also detected. cgMLST analysis demonstrated that NOVC strains from seafood cluster with clinical NOVC strains. Antimicrobial susceptibility testing (AST) results in the identification of five strains that developed non-wildtype phenotypes (medium and resistant) against the substances of the classes of beta-lactams (including penicillin, carbapenem, and cephalosporin), polymyxins, and sulphonamides. The phenotypic resistance pattern could be partially attributed to the acquired resistance determinants identified via in silico analysis. Our results showed differences in the virulence potential of the analyzed NOVC isolated from retail seafood products, which may be considered for further pathogenicity evaluation and the risk assessment of NOVC isolates in future seafood monitoring.

Isolation and Identification of Non-O1/Non-O139 Vibrio cholerae in Wild Birds Inhabiting Wetlands in Metropolitan Lima, Peru.

During a survey in wetlands from southern Lima, Peru, two non-O1/non-O139 Vibrio cholerae isolates were obtained from samples collected from an American Oystercatcher (Haematopus palliatus) and a Wren-like Rushbird (Phleocryptes melanops). Vibrio cholerae was identified by amplification and sequencing of 16S rRNA, differentially grown on CHROMagar Vibrio media, and confirmed by ompW amplification. Isolates were confirmed to be non-O1/non-O139 serotypes and to lack the ctxA gene as inferred using PCR. Susceptibility to eight antimicrobial agents was assessed, with one isolate being resistant to azithromycin, doxycycline, tetracycline, and furazolidone. Our results indicate the utility of surveillance for V. cholerae in wetlands in the metropolitan Lima area.

Bacteremia Caused by a Serotype Ob5 Vibrio cholerae Strain in a Cirrhotic Patient in China.

The increasing incidence of non-O1/non-O139 Vibrio cholerae (NOVC) has been observed worldwide. However, septicemia caused by NOVC remains a rare condition that has received limited attention. Currently, there are no established treatment guidelines for bloodstream infections caused by NOVC, and the understanding of this condition mainly relies on individual case reports. Although NOVC bacteremia can be fatal in a small percentage of cases, knowledge about its microbiological features remains limited. Here, we present a case of V. cholerae septicemia caused by NOVC in a 46-year-old man with chronic viral hepatitis and liver cirrhosis. The isolated strain, named V. cholerae VCH20210731 and classified as a new sequence type (ST), ST1553, was found to be susceptible to most of the antimicrobial agents tested. O-antigen serotyping of V. cholerae VCH20210731 revealed that it belonged to serotype Ob5. Interestingly, the ctxAB genes, which are typically associated with V. cholerae, were absent in VCH20210731. However, the strain possessed 25 other potential virulence genes, such as hlyA, luxS, hap, and rtxA. The resistome of V. cholerae VCH20210731 included several genes, including qnrVC4, crp, almG, and parE. Nevertheless, susceptibility testing demonstrated that the isolate was susceptible to most of the antimicrobial agents tested. Phylogenetic analysis indicated that the closest strain to VCH20210731 was strain 120 from Russia, differing by 630 single-nucleotide polymorphisms (SNPs). Our findings contribute to the understanding of the genomic epidemiological characteristics and antibiotic resistance mechanisms of this invasive bacterial pathogen. IMPORTANCE This study highlights the discovery of a novel ST1553 V. cholerae strain in China, providing valuable insights into the genomic epidemiology and global transmission dynamics of V. cholerae. It is important to note that clinical presentations of NOVC bacteremia can vary significantly, and the isolates demonstrate genetic diversity. Consequently, health care professionals and public health experts should remain vigilant about the potential for infection with this pathogen, particularly considering the elevated prevalence of liver disease in China.

Spectrum of ctxB genotypes, antibiogram profiles and virulence genes of Vibrio cholerae serogroups isolated from environmental water sources from Odisha, India

BackgroundThe present study reports on the comprehensive analysis of Vibrio cholerae O1 and non-O1/non-O139 serogroups isolated from environmental water sources during cholera outbreaks, epidemics and surveillance studies between years 2007 to 2019 from different districts of Odisha, India.MethodsA total of 85 stocked cultures of V. cholerae O1 and non-O1/non-O139 strains were analyzed for different ctxB genotypes, toxic genes, antibiogram profiles through PCR assays and pulsotyped by pulsed-field gel electrophoresis (PFGE).ResultsFrom all V. cholerae strains tested, 51 isolates were O1 Ogawa and the rest 34 strains were non-O1/non-O139. All the V. cholerae O1 strains were altered El Tor variants carrying ctxB1, ctxB3 and ctxB7 genotypes. However, only ctxB1 genotypes were present in V. cholerae non-O1/non-O139. Though non-O1/non-O139 strains were negative by O1 antisera, 20% strains were positive for rfbO1 gene by PCR assay. All the V. cholerae isolates possessed a variety of virulence genes including ace, ctxAB, toxR, zot, hlyA which were in higher percentage in the case of V. cholerae O1. The Vibrio cholerae O1 and non-O1-/non-O139 strains showed multiple antibiotic resistances in 2007 and 2012. The PCR detection of four resistance associated genes (strB, dfrA1, sulll, SXT) confirmed higher prevalence in V. cholerae non-O1/non-O139 strains. The PFGE analysis revealed 3 pulsotypes having 93% similarity among V. cholerae O1 strains.ConclusionThis study indicates the changing epidemiology, antibiogram patterns and continuous genetic variation in environmental V. cholerae strains of Odisha over the years. So continuous surveillance is necessary to understand the changing patterns of V. cholerae different serogroups isolated from stool and water samples from Odisha.

Transcriptome-wide identification and characterization of the Macrobrachium rosenbergii microRNAs potentially related to immunity against non-O1 Vibrio cholerae infection

Non-O1 Vibrio cholerae, a member of the Vibrio family, could cause gastrointestinal infection of Macrobrachium rosenbergii and result in significant economic losses. However, few studies on microRNA immunity related to non-O1 V. cholerae infection of M. rosenbergii. The aim of this study was to elucidate the mechanism of miRNA in the potential immune response of M. rosenbergii. to non-O1 V. cholerae MSVC-GY01 infection by transcriptome sequencing. Following quality screening, the control group received 10, 616, 712 clean reads, whereas the infected group received 9,727,616. The miRNA sequences in the two samples are extremely consistent and have a length of roughly 23 nt. In all, 871 known miRNAs were discovered, with 279 differentially expressed miRNAs (DEMs). Meanwhile, 62 novel miRNAs were predicted, including 43 DEMs. In order to understand the immune-related biological functions of DEMs, target genes were predicted. Pathway function annotation analysis showed that non-O1 V. cholerae affected the NOD-like receptor signaling pathway, RIG-I-like receptor signaling pathway, and Toll-like receptor signaling pathway, suggesting that miRNAs in the hepatopancreas play a key role in immune responses to pattern recognition receptors. Twelve DEMs were randomly selected for Quantitative Real-time PCR (qRT-PCR). Overall, the expression trends of qRT-PCR were consistent with the sequencing results. These findings corroborate the immunomodulatory function of miRNA in M. rosenbergii against non-O1 V. cholerae infection and provide guidance for the prevention and treatment of related illnesses.

Etiology and clinical features of non-O1/non-O139 Vibrio cholerae infection in an inland city in China.

Non-O1/non-O139Vibrio cholerae (NOVC) causesvarious illnesses ranging in severity from mild to life-threatening but were ignored previously. Knowledge of the NOVC infection, particularly bacteremia, is limited because of its rarity. Here we first retrospectively reported the demographic, clinical, and therapy characteristics of patients with NOVC infection. Isolated NOVC stains were identified by a series of biochemical, mass spectrometry (MS), and serum agglutination tests. The results of 11 patients with NOVC infection (including 8 with bacteremia) with a median age of 68 years were included in this report. Most isolated NOVC strains had antibiotic susceptibility. Patients with NOVC-positive were distributed in various departments, most occurring in gastroenterology (6 cases). Hepatic disease was the most common comorbid disease, followed by diabetes (3 cases) and biliary tract disease (3 cases). Two cases were previously healthy. The most common symptom at presentation was fever. All patients presented with abnormal changes in hematology and inflammatory parameters. Cephalosporins were the most frequently used antibiotics. Ten patients had a favorable outcome after treatment; one died from complicated underlying diseases. In summary, we recommend the timely identification of NOVC strains using MALDI-TOF-MS. The suspicion of NOVC bacteremia cannot be ruled out regardless of the host's immune status. An alternative therapeutic regimen for this infection may be β-lactam antibiotics or combined with β-lactamase inhibitors. Regardless, the specific therapeutic regimen should be based on the antibiogram data.

Vibrio cholerae: a pathogen shared by human and aquatic animals

Vibrio cholerae: a pathogen shared by human and aquatic animals

Death in a farmer with underlying diseases carrying Vibrio cholerae non-O1/non-O139 producing zonula occludens toxin

ObjectivesThe non-O1/non-O139 Vibrio cholerae caused outbreaks or sporadic cases of gastroenteritis that was rarely seen in good sanitary condition. It was described a case of systemic multiple organ lesions that worsened because of non-O1/non-O139 V. cholerae, suggesting that serogroups have a potential virulence in enhancing pathogenicity with patients with underlying diseases compared with a healthy population. Design or methodsSamples are identified by strain culture, polymerase chain reaction (PCR) virulence identification, and whole genome sequencing. ResultsA middle-aged man was diagnosed with cytotoxin-producing and nontoxin V. cholerae non-O1/non-O139 serogroups. Although lacking the CT toxin encoded by ctxAB gene, the pathogenesis of cholera relies on the synergistic action of many other genes, especially virulence genes. ConclusionsThis case suggested that the laborers engaging in agricultural production are at potential risk of V. cholerae infection by exposure of open wounds to contaminated water . However, epidemiological investigation should focus on the objective cause of the change of working environment. Furthermore, common diseases can possibly enhance the virulence of non-O1/non-O139 serogroups by attacking the tight junction of small intestinal epithelial cells, further triggering bacteremia, a process that may lead to death within 48–72 hours, which requires great attention.

Identification of Vibrio cholerae as a bacterial pathogen of bluegill sunfish

Bluegill sunfish (Lepomis macrochirus) is an important economic fish, which originated from North America. It was introduced to China in 1987 and is now widely bred in Guangdong Province. In recent years, a fatal bacterial disease often occurs in cultured bluegill sunfish. The clinical manifestations of the diseased bluegill sunfish were ulceration and hyperemia. A bacterial pathogen temporarily named TY01 was isolated from the internal organs of diseased fish. It was identified as non-O1/non-O139 Vibrio cholerae by morphological, serotype identification, biochemical and 16S rDNA phylogenetic analysis. The regression infection experiment confirmed that the isolated strain could cause the disease of healthy bluegill sunfish. The antibiotic susceptibility showed that TY01 was sensitive to chloramphenicol, azithromycin, tetracycline, doxycycline, neomycin, enoxacin and norfloxacin, and moderately sensitive or resistant to the other drugs. In this study, Vibrio cholerae was isolated and identified from diseased bluegill sunfish for the first time, and it provides a basis for the diagnosis, prevention and treatment of the disease.